Secrets of wasabi

  1. Wasabia japonica|
  2. How wasabi grows|
  3. Roots, stalks, leaves and flowers|
  4. The history of wasabi|
  5. Wasabi in Japanese cuisine|
  6. Health benefits of wasabi|
  7. Wasabi's kick

Wasabia japonica

Wasabi (wasabia japonica) is a condiment that belongs to the mustard family along with plants like horseradish and daikon radish. All mustard-type plants have a similar fragrance but there is nothing quite like the kick that accompanies wasabi’s unique aroma and flavor.

Wasabi originated in Asia and today is used in a variety of Japanese dishes. It is grown throughout Japan and even its scientific name is wasabia japonica. As perhaps the most widely recognized Japanese condiment in the world, it is called by its Japanese name in numerous languages.

  • Wasabia japonica
  • Wasabia japonica

How wasabi grows

How wasabi grows

Wasabi has grown wild in Japan’s mountainous regions since ancient times. Full-scale cultivation of the wasabi plant began during the Edo period (1603 – 1868). Because the plant is so delicate and can only grow under certain conditions, it is still considered a precious commodity among spices.

Wasabi grows naturally in relatively cold, clear mountain streams. It also requires a north-facing environment with fairly stable weather conditions year-round. Even in the right environment, it takes two to four years for a wasabi plant to grow large enough to be harvested. Owing to strict cultivation requirements and lengthy growing time, it’s only natural that wasabi commands a high price.

How wasabi grows

But wasabi can also grow outside of clear streams if planted in extremely wet soil in a cool mountain region with relatively little sunlight.

There are two varieties of wasabi: sawa (mountain stream) wasabi, which grows in shallow, clear-flowing water and oka (land) or hata (field) wasabi, which grows in soil. Though grown in slightly different environments, there is no difference in quality between the two. Plus, field-cultivated wasabi is less expensive since it is easier to produce in large quantities. Successful field cultivation is one of the reasons that tube wasabi is now gaining popularity worldwide.

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Roots, stalks, leaves and flowers

Grated wasabi that is eaten with sushi or sashimi is shaved from the
fat, gnarled root of the wasabi plant. Stalks shoot out from the
top of the root, ending in large, heart-shaped leaves. Tiny, cross-
shaped white flowers are in bloom from winter through early
summer. The delicate look of the plant belies its powerful punch.

Japanese eat the stalks, leaves and flowers of wasabi as well.
Stalks and leaves are typically pickled, and also chopped and
served as a topping for vegetable dishes and soups.

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The history of wasabi

  • 平安時代の絵巻物

    Clothes worn by nobility during the Heian period (794 - 1185).

  • 鎌倉時代の武将絵巻物

    Bronze statue of Minamoto no Yoritomo, founder and first shogun of the Kamakura shogunate.

Wasabi has been a part of Japanese life for centuries. As a result, the country has developed a unique wasabi culture that revolves around the kitchen.

The oldest wasabi records (from the 10th century)
Wasabi was noted in Japan as far back as the 10th century according to ancient records. The Chinese characters used to write “wasabi” in Japanese first appeared circa 918 in the Honzo Wamyo botanical medical dictionary and are still in use today.

Japan’s oldest book of basic laws and regulations, the Engishiki, was also written during this time. Completed in 927, it lists wasabi as an item that could be used to pay taxes imposed by the central government. During this time it is believed that wasabi was used both as food and medicine.

A staple of Japanese food culture (1000 – 1500)
There are written records of vegetarian wasabi dishes — primarily served at Buddhist temples — that date back to the Middle Ages. During the Kamakura period (circa 1185 – 1333), wasabi was chopped and used as an ingredient in chilled soups. Gradually, dishes like these spread to the general population. More uses were found for wasabi during the Muromachi period (1338 – 1573). Records from the time include descriptions of carp sashimi flavored with wasabi-infused vinegar.

Full-scale cultivation (1501 – 1900)
Prior to the 16th century Japanese used wasabi that grew naturally in mountainous regions. By the end of the Azuchi-Momoyama period (1573 – 1603), however, they began to cultivate the plant. The first to do so were local villagers in central Japan where wasabi already grew naturally: the clear headwaters of rivers flowing through what today is Shizuoka prefecture.

Sunpu Castle, former residence of Tokugawa Ieyasu, and surrounding moat.

Wasabi was also presented to Ieyasu Tokugawa, founder of the Edo Shogunate (1603 – 1868). He became nearly obsessed with its amazing qualities and is said to have forbidden its sale outside the Tokugawa family. This is thought to be because wasabi leaves strongly resemble hollyhock leaves, which are found in the Tokugawa family crest.

Full-scale wasabi cultivation eventually began in 1774 in the Amagi area of Izu, Shizoka prefecture — a region then under direct control of the Shogunate. Amagi is still a major wasabi production region today.

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Wasabi in Japanese cuisine


Sashimi is a staple of the Japanese diet and it is almost never eaten without wasabi. Wasabi’s punch counters the scent of raw fish and compliments its flavor with a light, fresh taste. It is also thought to have antibacterial properties.

People probably began using wasabi as a condiment for sashimi during the middle of the Muromachi period (1338 – 1573). Today’s common practice of using a combination of soy sauce and wasabi to eat sashimi is believed to have started late in the Edo period.

Soba noodles

Soba noodles
Another meal that typically features wasabi is cold soba noodles. When this dish became popular as the perfect meal on a hot summer day, wasabi gained a second role in Japanese cuisine. The combination of wasabi and soba can be traced to the Azuchi-Momoyama period (1573 – 1603). An encyclopedia published in 1712 described wasabi as an essential condiment for soba, indicating that Japanese were eating them together by the Edo period (1603 – 1868).


Sushi is one of the most distinctive dishes of Japanese cuisine and is becoming increasingly popular around the world. Even kaiten (conveyor-belt) sushi restaurants are now appearing outside Japan. As with sashimi, wasabi is an essential accompaniment to these raw fish dishes. The use of wasabi in combination with sushi began early in the 19th century. By the mid-1800s sushi chefs were adding wasabi to sushi in Edo (now Tokyo), which was the birthplace of modern-day nigiri sushi. This type of sushi spread from Edo to Osaka, Nagoya and other major Japanese cities and is now found worldwide, making wasabi as globally recognized as sushi itself.

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Health benefits of wasabi

Wasabi’s unique kick and aroma are two of its best qualities and help stimulate the appetite. This in itself is good for the body but research has shown that wasabi has many more beneficial health properties.

Folk remedy
In addition to being eaten as a food, wasabi has long been used as a folk remedy in Japan as well. People with ailments such as rheumatism, neuralgia or bronchitis would place a wasabi-coated cloth on the affected area as an anti-inflammatory analgesic. This was another practical use for the active elements in wasabi.

Antibacterial agent
For generations Japanese have used wasabi with raw or nearly raw shellfish and seafood, including sashimi and sushi. Wasabi neutralizes the distinct odor of fresh fish while its light, refreshing flavor makes the perfect accent. It is also said to help prevent food poisoning.

Health benefits of wasabi

Recent research has shown that wasabi can be used as an effective antibacterial agent, preventing the spread of E-coli and other forms of bacteria as well as stopping the growth of mold and parasites. In pre-modern days Japanese had empirical evidence that wasabi stopped microbes from multiplying. Today researchers are developing products that utilize wasabi’s antibacterial properties, including wasabi sheets made by processing the plant into a thin film. Sheets like these could be used to line the inside of lunch box lids, for example, to prevent food from spoiling.

The future of wasabi
Whether as a food, medicine or antibacterial agent, wasabi has been integrated into many aspects of Japanese life. Still, modern-day research is revealing that it has even more beneficial health properties than first thought. For example, wasabi is known to combat clotting conditions such as cerebral and myocardial infarctions — leading causes of death both in Japan and other parts of the world.

Scientists have also found that wasabi can slow the spread of cancer. Although a diet rich in vegetables has long been known to help prevent the disease, it may be beneficial for one’s health to make wasabi a regular part of meals as well.

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Wasabi's kick

Though people in India and other Southeast Asian countries regularly cook with hot spices like cayenne pepper, many of them say wasabi is one of the spiciest things they have ever eaten.

The spiciness experienced when eating cayenne or black pepper is often described as painful. This is because spicy components like capsaicin or piperine generate the feeling of heat by stimulating pain receptors in the tongue and mouth. Wasabi is different in that its spicy components travel from the mouth through the nasal passages, stimulating the mucous membranes. Japanese express the vibrant tingling wasabi produces as it escapes the nose with the word tsuun! Just the sound of this word attests to wasabi’s short, sharp and powerful kick!

Allyl mustard oil is responsible for wasabi’s effect on the nose, but is not present in wasabi until the root is grated. Grating breaks down wasabi’s cellular structure, activating an enzyme called myrosinase. This in turn breaks down mustard oil glycosides in the wasabi to produce allyl mustard oil.

Wasabi's kick


Reviving wasabi's kick

Wasabi’s kick is produced by a powerful but brief reaction; if left out too long, wasabi weakens and loses its kick. It can be revived somewhat by adding a bit of lemon juice. This is because the lemon juice re-activates the myrosinase enzymes in wasabi.

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